The good Dr. Perry has designed an Iron Mole, capable of digging right through to the center of the Earth, and with the financial help of his former student, David, the Mole is built and ready to go. But on the day of testing something unexpected occurs, trapping the Dr. and David in the core of the Earth. Within the core, however, lies a land like none other, with tremendous sized beasts, man eating plants, and people! Yet these people are slaves to the Sagaths, and their masters the Majars, and soon David and the Dr. are too. It's up to them to find the secret of the powerful Majars then unite the slaves towards freedom. A classic tale by Edgar Rice Burroughs (Tarzan creator) is brought to life in this movie from 1976, but it has a more classic adventure feel that older films had, equalling in entertainment films like Journey to the Centre of the Earth, Fantastic Voyage, and the Time Machine.